Effect of incorporation POFA in cement mortar and desired benefits: a review

Palm oil fuel ash (POFA) is a by-product waste material more economical and environmentally friendly, resulted from production palm oil products. Lack of enough information on the advantages of POFA in the concrete production in various proportions was the main cause to select this work. This paper presents the advantages of POFA as a partial cement replacement in concrete production. This study recommends that researchers and academics should show more experimental works in order to illustrate the desired benefits from POFA as cement replacement, thus mitigate of environmental impacts

The present state of the use of eggshell powder in concrete: a review

Eggshell (ES) is a bio-waste material obtained from bakers and fast-food restaurants. This waste material is generally disposed of in landfills, causing health hazards and polluting the environment. Eggshell powder (ESP) has high amounts of calcium and can be combined with pozzolanic materials, such as fly ash, which have low calcium content. This paper presents the results of the latest studies on the utilization of ESP as a filler, cement and fine aggregate. The chemical composition, physical properties and fresh and hardened properties of ESP concrete at different proportions are also presented. Results indicate the potential of using ESP with other pozzolanic materials to improve concrete properties and reduce cement production, thereby minimizing environmental pollution. The compressive, flexural and tensile strengths have also been improved with the use of some materials with ESP as cement replacement. However, some studies reported a reduction when cement is replaced with high percentages of ESP, particularly those larger than 10%. Furthermore, the modulus of elasticity decreases with high levels of replacement. The specific gravity of ESP was found to be lower than that of cement. The durability and water absorption of concrete were reduced with the addition of ESP

Mathematical modelling and hybrid ACO-PSO technique for PV performance improvement

Photovoltaic (PV) solar energy systems have been playing an important role in the field of energy generation for the last few decades. For such systems to attain the maximum efficiency and reliability in power generation, certain factors should be considered to improve the extracted power. For the purpose, this thesis is focused on some of the most important issues, assisting to improve the extracted power status. One of the most important issue for each PV system is the modelling of PV cells and the modules; the accuracy of these models is the main target in building any PV system. Therefore, this study is focused on developing an accurate and reliable PV model, based on five main parameters; the photocurrent, Iph, the reverse diode saturation current, Io, the ideality factor of diode, n, the series resistance, Rs, and the shunt resistance, Rsh. Performance of these five solar cell parameters (Iph, Io, n, RS, Rsh) and their effect on both the Current–Voltage (I–V) and Power–Voltage (P–V) characteristic curves, were tested and compared with other models, respectively. Firstly, the photocurrent, Iph effect was studied; the results showed that the increase in the Iph leads to an increase in the maximum power point (MPP) in a prominent way. In addition to this increment in MPP, an increase in the values of Isc and Voc were also observed. With an increase in Io, a regular increasing mode was observed in MPP, the Isc and Voc values in a similar manner. The value of changing n, showed no effect on Isc and Voc values, but increasing n values lead to a decrease in MPP values in the P–V characteristic curve. The increasing Rs values exhibited a decrease in the value of MPP, while not affecting the the Isc and Voc values, in a smiliar pattern with increasing n values. Finally, the effect of Rsh value was also tested; showed a barely noticeable effect on MPP, Isc , and Voc values. Secondly, a hybrid Ant Colony Optimisation-Particle Swarm Optimisation (ACO-PSO) algorithm was proposed to optimally determine the MPPT parameters. To improve the overall performance of the maximum power point (MPPT) system, the efforts of oscillation filtering and noise suppression were taken in this design, as well as the time response and the settling time. The proposed method is employed to track the global MPP under different shadow conditions, based on three different irradiation levels to test the ability and accuracy of the proposed method. The results of tracking MPP by the proposed MPPT technique showed that the improved method tracked the MPP for all the tested cases with a reasonable accuracy and in a very short convergence time as compared to the P&O method. Thirdly, to develop a new configuration incorporates ACO-PSO and PID to improve the steady state condition after tracking the MPP. The improved PID controller had contributed in attaining the steady state condition and assuring that there is no oscillation around the MPP. In the comparison with the P&O method, it still has a notable oscillation around the MPP, which results in decreasing the efficiency of the extracted power from the PV system. Moreover, in this study, two 5 kWp PV plants from two different PV technologies (mono-crystalline silicon (c-Si) and copper–indium–diselenide (CIS)) were used to validate the PV model performance based on energy generation, energy efficiency, and the performance ratio. Also, two different models from the literature were used to validate the PV model performance. For all of the validation factors, the energy generated, energy efficiency, and performance ratio of the proposed model showed that it is approximately fitting the real results for both of the CIS and c-Si plants with high level of accuracy than the compared models

Maximum Power Prediction for PV System based on P&O Algorithm

This research presents a maximum power point tracking (MPPT) controller for PV systems is proposed. The developing of the proposed controller is based on conventional P&O algorithm and an Artificial Neural Network. The voltage of the optimum PV system is predicted by using ANN as a controller in order to get the maximum point of power (MPP). The three inputs for the modelled ANN are temperature coefficients, ambient temperature, and solar radiation. While, the output voltage represents the ANN output node. The simulation result shows that ANN much faster than P&Q algorithm in which the output voltage prediction is take 4.91 second as compared to conventional P&O algorithm which is 9.69 second

Solar Cell Parameters Extraction Based on Single and Double-Diode Models: A Review

This paper comprehensively describes and discusses the extraction of the DC parameters of solar cells by mathematical techniques based on single-diode and double-diode models. The main parameters of interest are the photocurrent, Iph, the reverse diode saturation current, Io, the ideality factor of diode, n, the series resistance, RS, and the shunt resistance, RSh. This paper reviews the foremost issues of the condition of the methodologies of the extraction of PV solar cell parameters. This paper classifies the reviewed models on the basis of the number of extracted parameters and provides specific comments for each model. Five parameters from different models that have identical attributes are characterized with respect to irradiance and temperature to demonstrate the behavior and characteristics of these parameters. In addition, this article implements two real models, single-diode and double-diode models, and examines the performance of the PV parameters for each model and its effect on the current–voltage (I–V) and power–voltage (P–V) characteristics. Furthermore, to assess the accuracy of each model with respect to the data provided by the manufacturer, this paper compares the I–V and P–V curves at standard test condition (STC) and for different parameters for a generic PV panel

A Proposed Method of Photovoltaic Solar Array Configuration Under Different Partial Shadow Conditions

The benefit of improving the efficiency of photovoltaic(PV) solar system has come into view because of increasing the demand for electricity, especially in the urban areas. However, these PV solar systems are vulnerable to the mismatch operating conditions. Under such conditions, the performance of solar cells decreases rapidly since the non—uniform insolation hitting the cell sand with different values. Then this leads to cause rapidly decreasing in the output power value and maximum power point, beside to hot spot points that may be occur on the solar cell which finally leads to damage these cells. This paper proposes an optimal connection of sub strings with different value of shadow conditions, based on a thorough configuration that can significantly reduce that non—uniform conditions loss. The refinement over existing photovoltaic (PV) solar array interconnections is proven by extensive simulation results by using MATLAB SIMULINK

Five Parameter PV Model Extraction and Improvement Based on Experimental Data

This paper presents a new approach of the single diode five parameters model extraction and performance evaluation. The proposed model is capable of analytically describing the I–V and P–V characteristics of a PV module in different conditions. The PV parameters identify, mainly, the accuracy of any PV model. The proposed model constructed in a method to be in a sounds level of accuracy and far from complication. In term of accuracy, different evaluation criteria have being used in this study, and results of all criteria showed merit level of accuracy comparison to those in the compared models. In addition, the performance of the five parameters has been improved and this improvement showed in the I–V and P–V characteristics. Effect of these five parameters on all of the maximum power point (MPP), short circuit current (Isc), and open circuit voltage (Voc) also showed in the results. The outcomes of this study could help in improving the total PV system performance and could be a guide for method of extraction the five parameters model, since it dependent mainly on real results

Factor Affecting of BIM Technique in the Construction Firms in Iraq

The construction industry in Iraq became much more difficult than before because of complexities in the diagrams and documentations in the construction projects. Building information modeling (BIM) started to appear with entry the foreign companies to build the large projects in Iraq. It is a bode well technique for the construction industry, it has many benefits in all project phases from planning and scheduling to operation and demolition phase. This paper concentrated on the implementation of BIM technology and identify the benefits desired and challenges that reduce adoption this technique in the Iraqi construction industry. A qualitative approach has been used to collect data from two experts in the construction field in Iraq to show the factors affected on using BIM in the Iraqi construction firms. The results indicate to a rare implementation of BIM technology among construction professionals in Iraq. The study recommended encouraging the investment in the Iraqi construction markets to share the knowledge and experiences related to BIM technology between the construction professionals

Implementation of 4D/BIM in the Iraqi construction industry

Building information modelling (BIM) is a new technique, which has been innovated from the traditional method to a modern form. BIM should be classified as a modern technique, since it is dealing with digital data. 3D BIM with its time schedule results on 4D/BIM is represented by softwares, such as Naviswork and Syncro, which has an advantage to solve most of the project issues such as clash detection among projects components, visualisation to projects tasks, and other benefits. The aim of this current study is to find out the benefits and challenges of 4D/BIM implementation in the construction projects. The data collection method in this research is done by conducting semi-structured interviews (SSIs) with the senior civil engineer in Al-Najaf hospital project in Iraq, in addition to that there is the extensive literature review about the benefits, challenges and obstacles in the implementation of 4D/BIM. Analysis of the results was conducted by adopting content analysis method (CAM). The results proved that the construction industry in Iraq needs to further support from the government by increasing awareness and financial support for construction companies

Comparison study between POFA and POCP in terms of chemical composition and physical properties - review paper

High volume waste from agriculture industry can be utilized in concrete production instead of causing environmental problems. Palm oil fuel ash POFA and palm oil clinker powder POCP are two agricultural wastes resulted from palm oil industry. The high content of silica oxide SiO2 in the POFA and POCP are responsible for pozzolanic reaction required to improve the hydration products in the concrete mixture. However, both of POFA and POCP can be used as greener cement due to the small particle size and high surface area required to improve the mechanical properties of concrete. In addition to reduce the environmental problems due to accumulate the agriculture waste in landfills and open area